const base = { weight: '50kg', age: 18, hobby: ['eating', 'drinking'] }

const Bob = Object.assign({}, base)

Bob.age = 20
Bob.hobby.push('coding')

// 缺陷2: 深层次对象仍然会被修改
console.log(base) //=> { weight: '50kg', age: 18, hobby: [ 'eating', 'drinking', 'coding' ] }
console.log(Bob) //=> { weight: '50kg', age: 20, hobby: [ 'eating', 'drinking', 'coding' ] }
